Function destructor

ThirdParty/libproj/vtklibproj/src/transformations/vgridshift.cpp:139–147

}

static PJ *destructor (PJ *P, int errlev) {
    if (nullptr==P)
        return nullptr;

    delete static_cast<struct vgridshiftData*>(P->opaque);
    P->opaque = nullptr;

    return pj_default_destructor(P, errlev);
}

static void reassign_context( PJ* P, PJ_CONTEXT* ctx )
{